OK, let's crack this. We're given 890 and our task is to multiply it by 3. Essentially, we'll be adding 890 to itself 3 times.
Step 1: 0 + 890 = 890
Step 2: 890 + 890 = 1780
Step 3: 1780 + 890 = 2670

So, 890*3 = 2670